ftrace: add module globbing
Extend module command for function filter selection with globbing.
It uses the same globbing as function filter.
sh# echo '*alloc*:mod:*' > set_ftrace_filter
Will trace any function with the letters 'alloc' in the name in any
module but not in kernel.
sh# echo '!*alloc*:mod:ipv6' >> set_ftrace_filter
Will prevent from tracing functions with 'alloc' in the name from module
ipv6 (do not forget to append to set_ftrace_filter file).
sh# echo '*alloc*:mod:!ipv6' > set_ftrace_filter
Will trace functions with 'alloc' in the name from kernel and any
module except ipv6.
sh# echo '*alloc*:mod:!*' > set_ftrace_filter
Will trace any function with the letters 'alloc' in the name only from
kernel, but not from any module.
sh# echo '*:mod:!*' > set_ftrace_filter
or
sh# echo ':mod:!' > set_ftrace_filter
Will trace every function in the kernel, but will not trace functions
from any module.
sh# echo '*:mod:*' > set_ftrace_filter
or
sh# echo ':mod:' > set_ftrace_filter
As the opposite will trace all functions from all modules, but not from
kernel.
sh# echo '*:mod:*snd*' > set_ftrace_filter
Will trace your sound drivers only (if any).
Link: http://lkml.kernel.org/r/1443545176-3215-4-git-send-email-0x7f454c46@gmail.com
Signed-off-by: Dmitry Safonov <0x7f454c46@gmail.com>
[ Made format changes ]
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c
index 450a5f5..ea27250 100644
--- a/kernel/trace/ftrace.c
+++ b/kernel/trace/ftrace.c
@@ -3485,19 +3485,37 @@
}
static int
-ftrace_match_record(struct dyn_ftrace *rec,
- char *mod, struct ftrace_glob *func_g)
+ftrace_match_record(struct dyn_ftrace *rec, struct ftrace_glob *func_g,
+ struct ftrace_glob *mod_g, int exclude_mod)
{
char str[KSYM_SYMBOL_LEN];
char *modname;
kallsyms_lookup(rec->ip, NULL, NULL, &modname, str);
- if (mod) {
- /* module lookup requires matching the module */
- if (!modname || strcmp(modname, mod))
+ if (mod_g) {
+ int mod_matches = (modname) ? ftrace_match(modname, mod_g) : 0;
+
+ /* blank module name to match all modules */
+ if (!mod_g->len) {
+ /* blank module globbing: modname xor exclude_mod */
+ if ((!exclude_mod) != (!modname))
+ goto func_match;
+ return 0;
+ }
+
+ /* not matching the module */
+ if (!modname || !mod_matches) {
+ if (exclude_mod)
+ goto func_match;
+ else
+ return 0;
+ }
+
+ if (mod_matches && exclude_mod)
return 0;
+func_match:
/* blank search means to match all funcs in the mod */
if (!func_g->len)
return 1;
@@ -3512,23 +3530,32 @@
struct ftrace_page *pg;
struct dyn_ftrace *rec;
struct ftrace_glob func_g = { .type = MATCH_FULL };
+ struct ftrace_glob mod_g = { .type = MATCH_FULL };
+ struct ftrace_glob *mod_match = (mod) ? &mod_g : NULL;
+ int exclude_mod = 0;
int found = 0;
int ret;
int clear_filter;
- if (len) {
+ if (func) {
func_g.type = filter_parse_regex(func, len, &func_g.search,
&clear_filter);
func_g.len = strlen(func_g.search);
}
+ if (mod) {
+ mod_g.type = filter_parse_regex(mod, strlen(mod),
+ &mod_g.search, &exclude_mod);
+ mod_g.len = strlen(mod_g.search);
+ }
+
mutex_lock(&ftrace_lock);
if (unlikely(ftrace_disabled))
goto out_unlock;
do_for_each_ftrace_rec(pg, rec) {
- if (ftrace_match_record(rec, mod, &func_g)) {
+ if (ftrace_match_record(rec, &func_g, mod_match, exclude_mod)) {
ret = enter_record(hash, rec, clear_filter);
if (ret < 0) {
found = ret;
@@ -3568,17 +3595,11 @@
* you can tell which command was used by the cmd
* parameter.
*/
-
- /* we must have a module name */
- if (!module || !strlen(module))
- return -EINVAL;
-
ret = match_records(hash, func, strlen(func), module);
if (!ret)
return -EINVAL;
if (ret < 0)
return ret;
-
return 0;
}
@@ -3729,7 +3750,7 @@
do_for_each_ftrace_rec(pg, rec) {
- if (!ftrace_match_record(rec, NULL, &func_g))
+ if (!ftrace_match_record(rec, &func_g, NULL, 0))
continue;
entry = kmalloc(sizeof(*entry), GFP_KERNEL);
@@ -4621,7 +4642,7 @@
do_for_each_ftrace_rec(pg, rec) {
- if (ftrace_match_record(rec, NULL, &func_g)) {
+ if (ftrace_match_record(rec, &func_g, NULL, 0)) {
/* if it is in the array */
exists = false;
for (i = 0; i < *idx; i++) {